Read performance of a non-volatile memory device, in particular a non-volatile memory device with buried selection transistor
First Claim
Patent Images
1. A non-volatile memory device, comprising:
- a first twin pair of memory cells, the first twin pair including first and second memory cells arranged in a first column, the first and second memory cells each including a respective selection transistor and a respective state transistor, the selection transistors of the first twin pair having respective gate terminals coupled to one another;
a second twin pair of memory cells, the second twin pair including third and fourth memory cells arranged in the first column, the third memory cell being adjacent to the second memory cell, the third and fourth memory cells each including a respective selection transistor and a respective state transistor, the selection transistors of the second twin pair having respective gate terminals coupled to one another;
a first bitline coupled to conduction terminals of the state transistors of the first and fourth memory cells; and
a second bitline coupled to conduction terminals of the state transistors of the second and third memory cells, wherein each state transistor having a charge-trapping region and a control gate, the state transistor being configured to store a binary data value and selectively take first and second states respectively corresponding to two logical values of the binary data value, wherein the state transistor is a depletion-mode transistor and is configured, when a control voltage of zero is applied to the said control gate, to be conducting when the state transistor is in the first state and turned off when the state transistor is in the second state.
1 Assignment
0 Petitions
Accused Products
Abstract
The non-volatile memory device comprises memory cells each comprising a selectable state transistor having a floating gate and a control gate. The state transistor is of the depletion-mode type and is advantageously configured so as to have a threshold voltage that is preferably negative when the memory cell is in a virgin state. When the memory cell is read, a read voltage of zero may then be applied to the control gate and also to the control gates of the state transistors of all the memory cells of the memory device.
-
Citations
20 Claims
-
1. A non-volatile memory device, comprising:
-
a first twin pair of memory cells, the first twin pair including first and second memory cells arranged in a first column, the first and second memory cells each including a respective selection transistor and a respective state transistor, the selection transistors of the first twin pair having respective gate terminals coupled to one another; a second twin pair of memory cells, the second twin pair including third and fourth memory cells arranged in the first column, the third memory cell being adjacent to the second memory cell, the third and fourth memory cells each including a respective selection transistor and a respective state transistor, the selection transistors of the second twin pair having respective gate terminals coupled to one another; a first bitline coupled to conduction terminals of the state transistors of the first and fourth memory cells; and a second bitline coupled to conduction terminals of the state transistors of the second and third memory cells, wherein each state transistor having a charge-trapping region and a control gate, the state transistor being configured to store a binary data value and selectively take first and second states respectively corresponding to two logical values of the binary data value, wherein the state transistor is a depletion-mode transistor and is configured, when a control voltage of zero is applied to the said control gate, to be conducting when the state transistor is in the first state and turned off when the state transistor is in the second state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 18, 19, 20)
-
-
12. A method, comprising:
reading a non-volatile memory cell of a memory device that includes a memory plane including rows and columns of memory cells and two bit lines per column, each column of memory cells including pairs of twin memory cells, each pair of twin memory cells having two selection transistors sharing a common gate, two adjacent twin memory cells of the same column not being connected to the same bit line, and two adjacent memory cells of the same column that are not part of the same twin memory cell being connected to the same bit line, each memory cell including a selectable state transistor that is a depletion-mode transistor having a charge trapping region and a control gate, wherein the reading includes applying a read voltage of zero to the control gate of the state transistor of the non-volatile memory cell being read. - View Dependent Claims (13, 14, 15)
-
16. A non-volatile memory device, comprising:
-
a memory plane including rows and columns of memory cells, each memory cell including a selection transistor, having a control gate, and a selectable state transistor that is a depletion-mode transistor having a charge trapping region and a control gate, each column of memory cells including pairs of twin memory cells, the selection transistors of each pair of twin memory cells sharing a common gate; a plurality of gate control lines, each control gate line being electrically coupled to the control gates of the state transistors of the memory cells of a respective one of the rows; and a plurality of bit lines, each column of memory cells being connected to a respective pair of bit lines of the plurality of bit lines, two adjacent twin memory cells of the same column not being connected to the same bit line, and two adjacent memory cells of the same column that are not part of the same twin memory cell being connected to the same bit line. - View Dependent Claims (17)
-
Specification